Ducting system for HVAC application

Abstract

A ducting system for a heating ventilation and air conditioning (HVAC) application includes a duct assembly having an inner duct member, and an outer duct member disposed around the inner duct such that the outer and inner duct members together define a pre-determined amount of space therebetween. The ducting system also includes a bonding and insulation composite that is disposed in the pre-determined amount of space between the inner and outer duct members to insulate the inner and outer duct members from each other yet adhesively bond with each of the inner and outer duct members for imparting structural rigidity to the duct assembly.

What is claimed is: 
     
       1. A ducting system for a heating, venting and air conditioning (HVAC) application, the ducting system comprising:
 a duct assembly for the HVAC application comprising:
 a metallic inner duct member, and 
 a metallic outer duct member disposed around, and co-axially with, the inner duct member such that the outer and inner duct members together define a pre-determined amount of space contiguously therebetween; and 
 
 a bonding and insulation composite disposed in the pre-determined amount of space between the inner and outer duct members to insulate the inner and outer duct members from each other yet adhesively bond with each of the inner and outer duct members so as to impart structural rigidity to the duct assembly, wherein the bonding and insulation composite is:
 a closed-cell Polyurethane and resin mixture formed within the pre-determined amount of space contiguously between the inner and outer duct members such that the contiguously formed bonding and insulation composite is a thermal and fluid impermeable insulation configured to hermetically seal the space between the inner and outer duct members; and 
 
 an interfacing gasket disposed on at least one end of the duct assembly, wherein the interfacing gasket is a polymer. 
 
     
     
       2. The ducting system of  claim 1  further comprising a pair of adjacently located duct assemblies that are connected to each other by butting corresponding ones of inner and outer duct members from the pair of adjacently located duct assemblies with the interfacing gasket therebetween. 
     
     
       3. The ducting system of  claim 2 , wherein the outer duct member of each duct assembly includes an end that is configured to define thereon, a transverse duct flange (TDF) such that, in use, the TDF from one duct assembly is connected to a proximally located, and mutually opposing, TDF of another duct assembly from the pair of adjacently located duct assemblies. 
     
     
       4. The ducting system of  claim 1 , wherein the outer duct member is concentrically located with respect to the inner duct member. 
     
     
       5. The ducting system of  claim 4  further comprising a plurality of jigs disposed within the pre-determined amount of space between the inner and outer duct members, each jig from the plurality of jigs configured to connect the outer duct member and the inner duct member such that the pre-determined amount of space between the inner and outer duct members is uniform across a cross-sectional area of the duct assembly. 
     
     
       6. The ducting system of  claim 5 , wherein a width of the space is based on a desired amount of R-value between the inner and outer duct members. 
     
     
       7. The ducting system of  claim 6 , wherein the bonding and insulation composite is formed using a mixture having an R-value of not less than 13 if the width of the space between the outer and inner duct members is 2 inches. 
     
     
       8. The ducting system of  claim 1 , wherein the bonding and insulation composite is deposited within the pre-determined amount of space as flowable media, and wherein the flowable media expands and hardens into a non-flowable state over a pre-determined period of time prior to installation of the duct assembly within the HVAC application. 
     
     
       9. A method for forming a ducting system for a heating, venting and air conditioning (HVAC) application, the method comprising:
 forming a duct assembly for the HVAC application by:
 providing a metallic inner duct member; and 
 positioning a metallic outer duct member around, and co-axially with, the inner duct member such that the outer and inner duct members together define a pre-determined amount of space contiguously therebetween; and 
 
 providing a bonding and insulation composite within the pre-determined amount of space between the inner and outer duct members such that the bonding and insulation composite contiguously insulates the inner and outer duct members from each other yet adhesively bonds with each of the inner and outer duct members for imparting structural rigidity to the duct assembly, wherein the bonding and insulation composite is:
 a closed-cell Polyurethane and resin mixture formed within the pre-determined amount of space contiguously between the inner and outer duct members such that the contiguously formed bonding and insulation composite is a thermal and fluid impermeable insulation configured to hermetically seal the space between the inner and outer duct members; and 
 
 providing an interfacing gasket on at least one end of the duct assembly, wherein the interfacing gasket is a polymer. 
 
     
     
       10. The method of  claim 9  further comprising:
 providing a pair of adjacently located duct assemblies; and 
 connecting the pair of adjacently located duct assemblies to each other by butting corresponding ones of the outer duct members from the pair of adjacently located duct assemblies with the interfacing gasket therebetween. 
 
     
     
       11. The method of  claim 10  further comprising:
 forming a transverse duct flange (TDF) on an end of the outer duct member of each duct assembly; and 
 connecting the TDF from one duct assembly to a proximally located, and mutually opposing, TDF of another duct assembly from the pair of adjacently located duct assemblies. 
 
     
     
       12. The method of  claim 9  further comprising locating the outer duct member concentrically with respect to the inner duct member. 
     
     
       13. The method of  claim 12  further comprising providing a plurality of jigs within the pre-determined amount of space to connect the outer duct member and the inner duct member such that the pre-determined amount of space between the inner and outer duct members is uniform across a cross-sectional area of the duct assembly. 
     
     
       14. The method of  claim 13 , wherein a width of the space is based on a desired amount of R-value between the inner and outer duct members. 
     
     
       15. The method of  claim 14  further comprising using a mixture to form the bonding and insulation composite such that the bonding and insulation composite has an R-value of not less than 13 if width of the space between the outer and inner duct members is 2 inches. 
     
     
       16. The method of  claim 9 , wherein providing the bonding and insulation composite within the pre-determined amount of space includes depositing the bonding and insulation composite within the pre-determined amount of space as flowable media, and allowing the flowable media to expand and harden into a non-flowable state over a pre-determined period of time prior to installation of the duct assembly within the ducting system.